Tag Archives: evolution

Book Review: Daniel Lieberman’s The Story of the Human Body

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In The Story of the Human Body Daniel Lieberman builds a strong case that making fully informed decisions about diet and lifestyle is only possible through the lens of evolutionary history. If you want to know where your body comes from, you need to understand its evolutionary history. Why do humans stand and walk on two legs? Why are we weak compared to other primates of comparable size? Why are our legs and feet shaped the way they are, with springy tendons and arched feet? Why does our spine have a special S-curve? The answer to these questions lies in the the evolutionary history of our species.

Now ask, why do people in modern societies suffer from “diseases of affluence” like obesity, type-2 diabetes, tooth decay, metabolic syndrome, flat feet, nearsightedness, lower back pain, and sleep disorders? Daniel Lieberman argues that these questions can only be fully answered by understanding the evolutionary history of our species. Lieberman argues these diseases are examples of “mismatch diseases” i.e. a disease that is primarily caused by our bodies not being sufficiently adapted to novel gene-environment contexts. We know they’re mismatch diseases primarily because they used to be rare, are largely preventable, and are almost unheard of in hunter-gatherer populations.

Lieberman argues that all of these diseases are in some sense a result of cultural evolution speeding ahead of natural evolution with the result that have humans manufactured a psychologically comfy and satisfying environment that is paradoxically unhealthy without fundamentally affecting our reproductive fitness. Lieberman calls this this paradoxical unhealthiness “dysevolution”. It turns out that surrounding ourselves with unlimited sources of cheap junk food is a bad idea because humans are genetically wired to crave food with dense amounts of fat, sugar, starch, and salt.

Lieberman is no luddite, and certainly doesn’t advocate a return to the caves and giving up on modern science and technology. His position is more nuanced than many of the extreme black and white positions out there, as befitting the complexity of gene-environment interaction. In many senses, the agricultural and industrial revolutions have propelled humans to new heights of health and longevity, with modern science curing diseases and fixing people better than ever before. At the same time, we are living longer but spending many of those years suffering from chronic, preventable diseases. The paradox of the modern world is reduced mortality but greater morbidity i.e. living longer, but spending more of those extra years with an illness of some sort. Lieberman argues that too often the incentives of modern medicine aim at fixing symptoms but not the underlying structural causes: the toxically comfortable environments we built for ourselves.

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Quote for the Day – The Evolutionary Logic of Love

As Steven Pinker observes, the logic of loyalty is particularly clear in the domain of romantic relationships: You’re a great catch, but there is bound to be someone out there who’s got everything you’ve got plus a little more. Knowing that your partner might someday meet such a person, you’d be reassured by the knowledge that your partner isn’t going to leave you as soon as something better comes along. This would make you much more willing to settle down with your partner and start a family–a high-stakes cooperative endeavor if ever there was one. It’s wonderful that your partner fully appreciates your many marketable qualities, but that may not be enough to keep you together. What you really want is for your partner to have a deep, unshakable desire to be with you and you alone. In short, you want your partner to love you, to want you not only for your wonderful qualities but just because you’re you. Only love provides the kind of loyalty you need in order to take the parenting plunge. Thus, love appears to be more than just an intense form of caring. It’s a highly specialized piece of psychological machinery, an emotional straitjacket that enables cooperative parenting by assuring our parenting partners that they won’t be abandoned.

~Joshua Greene, Moral Tribes: Emotion, Reason, and the Gap Between Us and Them (2013), p. 42

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Book notice: Stephen J. Gould’s The Panda’s Thumb

A used copy of Stephen J. Gould’s book The Panda’s Thumb (1980) has been sitting on my shelf for a while, and I’m kicking myself for not reading it sooner. What a delightful little book of science essays! Each essay is an edited version of one of his monthly columns at Natural History magazine. Subsequently, the essays are intelligible to the general intelligent reader, but Gould does not thereby sacrifice an appreciation for hard facts and subtle reasoning. Gould makes science come alive with his anecdotes, wry humor, and gentle argumentation about topics ranging from the panda’s thumb to hopeful monsters and everything in between. Nothing is too big or small for Gould to think worthy of writing about. All in all, I highly recommend this book for any student of biology or lover of science.

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Quote for the Day – Is Evolutionary Biology Inherently Sexist? No, says Sarah Hrdy

Evolutionary biology, and its offspring, sociobiology, are not inherently sexist. The proportion of “sexists” among their proponents is probably no greater than the proportion among scientists generally. To be sure, contemporary analyses of mammalian breeding systems can cause even a committed Darwinian like myself to contemplate her gender with foreboding. Yet, it is all too easy to forget, while quaking, that sociobiology, if read as a prescription for life rather than a description of the way some creatures behave, makes it seem bad luck to be born either sex.

~Sarah Blaffer Hrdy, The Woman That Never Evolved, p. 14

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Quote for the Day – Evolutionary Biology, Social Darwinism, and Feminism

Social Darwinism has, almost indelibly, tainted most people’s understanding of evolutionary theory-certainly as it applies to human beings. Yet social Darwinism differs from Darwinism-without-adjectives in one all-important way, and ignoring this distinction has been one of the most unfortunate and long-lived mistakes of science journalism. Darwinism proper is devoted to analyzing all the diverse forms of life according to the theory of natural selection. Darwinists describe competition between unequal individuals, but they place no value judgment on either the competition or its outcome. Natural-selection theory provides a powerful way to understand the subordination of one individual, or group of individuals, by another, but it in no way attempts to condone (or condemn) subordination.

By contrast, social Darwinists attempt to justify social inequality. Social Darwinism explicitly assumes that competition leads to “improvement” of the species; the mechanism of improvement is the unequal survival of individuals and their offspring. Applying this theory to the human condition, social Darwinists hold that those individuals who win the competition, who survive and thrive, must necessarily be the “best.” Social inequalities between the sexes, or between classes or races, represent the operation of natural selection and therefore should not be tampered with, since such tampering would impede the progress of the species. It is this latter brand of Darwinism that became popularly associated with evolutionary biology. The association is incorrect, but it helps to explain why feminists have steadfastly resisted biological perspectives.

~Sarah Blaffer Hrdy, The Woman That Never Evolved, p. 12-13

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Quote for the Day – Sarah Blaffer Hrdy: We Are Composites

I was driven to understand my past. For we are not ready-made out of somebody’s rib. We are composites of many different legacies, put together from leftovers in an evolutionary process that has been going on for billions of years. Even the endorphins that made my labor pains tolerable came from molecules that humans still share with earthworms.

~Sarah Blaffer Hrdy, Mother Nature: A History of Mothers, Infants, and Natural Selection

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New paper completed: “A Genealogical Defense of Normative Nihilism” ; feedback welcome

“One ought not torture for fun.” Few would challenge this norm. But why? A common answer is that norms are “prescriptive”, telling us how we should act. Moreover, such norms are regarded as “authoritative”, possessed with a “binding force” that “governs” rational beings. What is the nature of this “normative force” and its “binding power”? Philosophers sometimes talk about different strengths of normative force, invoking the traditional distinction between hypothetical and categorical norms.

Hypothetical norms are “weakly” binding and exemplified by social conventions e.g. “One ought to use the small fork for salads.” Few people would consider it wrong to use the big fork because this norm only “binds us”if we want to impress high society. The force of hypothetical normativity is thus tied to our individual desires; if my desire to rebel against high society is stronger than my desire to fit in, I am hypothetically bound to not use the small fork.

In contrast, categorical norms such as “One ought not torture for fun” are “strongly” binding in the sense of not being conditional on anyone’s actual or ideal desires. If a psychopath desires to torture others for fun, they are nevertheless obligated to not torture for fun. Unlike their hypothetical cousins, categorical norms are considered “objectively prescriptive” (Mackie, 1977), enjoying what Aquinas calls “the binding force which is proper to a law”.

Suppose categorical force is merely a dressed up version of hypothetical force. How could we tell otherwise? The existence of a “binding” categorical force is not an obvious or trivial truth, nor detectable by any scientific instrument (that I know of). On these grounds alone, a skeptic might propose the “bindingness” of categorical force is merely hypothetical force masquerading as something stronger,a remnant of an old brain disposed for religiosity and magical thinking.

The normative realist claims categoricity is felt as forceful because it really is forceful in virtue of the binding power of “irreducible” normative facts. In contrast, the normative nihilist claims the bindingness of normativity derives its “force”merely from biological and cultural values, but there is no ultimate fact about which values are “better” than any other because, from the physicalist point of view, the universe is cold, uncaring, and ultimately valueless. Nietzsche’s statement of the worldview driving normative nihilism is definitive: “Whatever has value in our world now does not have value in itself, according to its nature—nature is always value-less, but has been given value at some time” (Nietzsche, 1974, p. 242, emphasis added). Nietzsche offers a “physiological” explanation of the source of normativity by tracing the concrete human origins of the concept of categoricity, explaining away the phenomenology of “binding” normative authority as a figment of an over-active brain.

Critics accuse normative nihilists of being either incoherent or hypocritical because in defending the view they “help themselves” to normative concepts, and thus undermine their own attempts at making a meaningful, rational, or intelligible claim. Thus, normativists are doubtful genealogical stories have any revisionary implications for our normative concepts. And even if they did, normativists pull out their trump card tu quoque argument: even if an evolutionary critique of moral norms were successful, it would thereby “prove too much” by casting doubt on all norms, including the epistemic norms that rationally “bind” nihilists to avoid saying “This genealogy both happened and did not happen.” Skeptics have dealt with this “global” challenge creatively, but few have opted to bite the bullet on epistemic nihilism for fear of committing “intellectual suicide” (Sorensen, 2013).Philosophers are by professional reputation defenders of epistemic authority and—not surprisingly—tend to dismiss the prospect of Global Normative Nihilism(GNN)as absurd or self-defeating.

My central thesis is once we distinguish between hypothetical and categorical strengths of epistemic authority the charge of self-defeat rings hollows, for the following reason. If epistemic norms only “bind” us hypothetically with respect to our contingently held desires and/or values, pointing out epistemic nihilists have “binding” hypothetical reasons to avoid holding contradictory beliefs is consistent with the nihilistic claim that acting in accord with epistemic norms is not good in-itself, because nature is valueless. The psychological inevitability of normal humans to feel “bound”by epistemic norms does not entail we are categorically bound to follow them. Naturalists have no beef with hypothetical forms of “binding force” because this locution is understood as a conceptual metaphor. The naturalistic worldview driving normative nihilism predicts that organisms project hypothetically binding values on a valueless world.

Read the full paper HERE: Williams – Genealogy QP 2 version 1.7 8-16-2013

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